Current U.S. vaccines use the pre-fusion spike protein, making antibody-dependent enhancement (ADE) unlikely.

“That's what we have in all of our U.S. vaccines, the pre-fusion viral protein, the pre-fusion spike protein. We are not making post-fusion antibodies against the spike protein, which is so reassuring that antibody-dependent enhancement is so...it's so unlikely to happen because we don't make those antibodies.”

“So what the brilliant work of Jason McLellan showed is that you could basically lock a viral protein into the pre-fusion complex, and when you then, you know, use that pre-fusion viral protein in a vaccine, you don't make post-fusion antibodies because you don't...your body isn't exposed to that structure of the viral protein.”